1. Field of the Invention
The invention relates to a haymaking machine, in particular a windrower for plants lying on the ground.
Windrowers are suited to the harvesting of cut fodder lying on the ground, these machines provided with a rotor and movable tools make it possible to gather the fodder in windrows intended to be subsequently picked up for example by means of presses.
2. Description of the Related Art
Windrowers comprise a support structure including a main beam on which is articulated at least one lateral arm which is movable around an axis by a jack and which carries at least one windrowing rotor. Windrowers usually comprise several rotors staggered along the support structure so as to cover a large work area during the movement of the agricultural machine on a field or a meadow.
Agricultural machines operate on all types of terrain, therefore the tools and equipment which are used by farmers must adapt themselves depending on the relief of these terrains.
The windrower is brought to work in fields which may be sloping or on irregular terrains, or else comprising obstacles. To permit this work, the rotor of the windrower usually has a certain latitude of movement so as to follow the contours of the terrain, devices are provided, in addition, to raise the tools.
The latitude of movement of the rotor in operation is currently not adjustable and the displacements of the work tool are not controlled in a precise manner. Consequently, the articulation between the support arm of the rotor and the rotor is subjected to great stresses, there is thus a need to control the displacement of the rotor during work and during movements.
When the work in the field requires to raise the rotor, to pass an obstacle for example, or when the rotor is folded to the vertical for transport outside the work area, it is preferable if there is no unexpected movement which could cause damage for the articulation and the rotor itself if the rotor came to run into the frame. A problem thus appears which is to block the displacement of the rotor when the latter is not in work position.